RALEIGH, N.C. – Ruth Huber Bostic carefully tended to her flower garden every day, even though the rest of her home and property were in shambles. Neighbors said she appeared to talk to herself while she cared for the hosta plants and violets. These seemed to be moments of tranquility for a troubled elderly woman whose husband had apparently departed long ago. Then, more than a year after she died at age 78, police discovered Bostic had not been entirely alone during her daily garden visits: Underneath the ivy and bricks, detectives found the remains of her husband, David Ellis Bostic. David Ellis Bostic had been missing for at least 14 years before Ruth's death in 2010. Friends and family still wonder exactly what happened. "It's a mystery. Things happen no one ever expects," said Carl Willis, David Ellis Bostic's 59-year-old nephew and closest living relative. Willis lives in Newport News, Va., and last spoke to his uncle in 1994. Ruth Bostic seems to have been even more estranged from her family, who declined requests for interviews through police investigating the case. Authorities did learn that Ruth Bostic was born in upstate New York and turned over care of her daughter to the child's grandmother at an early age. They also found a history of mental illness. "Her family hadn't talked with her in years and years," Raleigh police Detective J.D. Faulk said. "They said she left home early to do some traveling in Europe. Over time, her mental problems got worse and worse." She also told tales: stories about working in Hitler's concentration camps and of her friendship with the czar of Russia. Neighbor Sandy Smith said the fantasies seemed to grow worse after David Ellis Bostic became sick in the mid-1990s: Ruth said he'd suffered a stroke, and Smith assumed he was in a nursing home. Bostic's Raleigh neighbors recall her as an eccentric woman who didn't want anyone nosing around her house or yard. None knew she had family of her own. "I thought she was just plain mean," said Marcus Larossi. "The only time I saw her was when she was fussing and cussing because somebody had walked in her yard or tried to knock on her door." For years, Bostic's post-war bungalow was considered an eyesore, with peeling paint, trash strewn about and weeds growing all along the driveway. When neighbors asked her to mow the front lawn, she had a mound of concrete poured in the yard instead. Bostic's mail man, Eddie Taylor, said he spoke with her occasionally and became familiar with her stories. "She'd talk to me every now and then, but I think she had most people around here scared of her," Taylor said. Willis said he only spoke to his uncle sporadically. The last time was at a 1994 Bostic family reunion in Rose Hill, N.C. That was also the occasion when Willis met Ruth. "We talked and she said some things about the emperor of China," Willis recalled. "But Ellis just shook his head and smiled. It was obvious she cared for him and he cared for her." A year or two later, Ruth called to tell Willis that her husband, born in 1912, was having health problems. Ruth said the couple was moving, possibly to New Jersey, where her sister worked in a nursing home. Willis said he waited for a follow up call with details of the relocation. As years went by, he began to lose hope. Once, on a business trip to Raleigh, he even drove through his uncle's old neighborhood. The wood-frame house looked abandoned, and he didn't bother to stop. Ruth Bostic died in her living room in January 2010. She was discovered a month later after Taylor realized she was no longer checking her mailbox. Police said her death was from natural causes. Within months, Raleigh police began to get inquiries about David Bostic's Social Security checks. Apparently they were being deposited into a joint account that was no longer active. The case intrigued detectives, who spent months searching the house, digging through public records, questioning neighbors and contacting distant family members to find traces of the missing man. There were few results — no death certificate or any record of his marriage to Ruth Bostic. "We found his voting record from 1996. That's the last time we can say he was alive," Detective Andy Murr said. After hearing stories about Ruth Bostic's gardening habits, detectives began to dig in the couple's yard. First they turned up the concrete slab out front, then moved to the back yard to the garden Ruth Bostic tended so lovingly. Police say the autopsy revealed nothing suspicious about David Bostic's death. Willis is left only with a list of questions. "Why didn't she call on family if she needed help? Why did she bury him in the yard? Did she do it alone? I guess these are questions that will never be answered." Follow Yahoo! News on Twitter , become a fan on Facebook